Write head with modified side shields

ABSTRACT

A write head, the write head having an air bearing surface, the write head including a magnetic write pole, wherein at the air bearing surface, the write pole has a trailing surface, a leading surface that is opposite the trailing surface, and first and second surfaces; a trailing shield proximate the trailing surface of the magnetic write pole; first and second gaps proximate the first and second surfaces of the magnetic write pole; first and second side shields proximate the first and second gaps, each of the first and second side shields having a trailing shield surface; and first and second antiferromagnetic-coupling layers positioned between the trailing shield surfaces of the first and second side shields and the trailing shield.

FIELD

This disclosure relates generally to write heads, and more specificallyto write heads that include at least side shields.

BACKGROUND

Utilization of side shields in write heads can affect in cross-trackgradients and therefore areal density. The use of side shields canhowever cause side track erasure (STE). STE can be caused by a number ofphenomena including flux leakage through the flare angle into the sideshields and into the media.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a write head according to an embodimentfrom the air bearing surface (ABS);

FIGS. 2A to 2D are schematic views of polarities of a write head thatdoes not include an antiferromagnetic-coupling layer (FIG. 2A) both inthe static case (FIG. 2B) and during an erasure event (FIG. 2D), and aschematic view of polarities of a write head that does include anantiferromagnetic-coupling layer according to an embodiment (FIG. 2C);

FIG. 3 is a schematic view of a write head that includes a layeredstructure according to an embodiment from the ABS showing thepolarities;

FIGS. 4A and 4B are schematic views of a write head with recessed sideshields according to an embodiment (FIG. 4A), and a write head withdifferent magnetic portions in side shields according to an embodiment(FIG. 4B); and

FIG. 5 is a graph showing the modified peak field versus the cross trackcoordinates for write heads according to embodiments and comparativewrite heads.

The figures are not necessarily to scale. Like numbers used in thefigures refer to like components. However, it will be understood thatthe use of a number to refer to a component in a given figure is notintended to limit the component in another figure labeled with the samenumber.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanying setof drawings that form a part hereof and in which are shown by way ofillustration several specific embodiments. It is to be understood thatother embodiments are contemplated and may be made without departingfrom the scope or spirit of the present disclosure. The followingdetailed description, therefore, is not to be taken in a limiting sense.

Unless otherwise indicated, all numbers expressing feature sizes,amounts, and physical properties used in the specification and claimsare to be understood as being modified in all instances by the term“about.” Accordingly, unless indicated to the contrary, the numericalparameters set forth in the foregoing specification and attached claimsare approximations that can vary depending upon the properties sought tobe obtained by those skilled in the art utilizing the teachingsdisclosed herein.

The recitation of numerical ranges by endpoints includes all numberssubsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3,3.80, 4, and 5) and any range within that range.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” encompass embodiments having pluralreferents, unless the content clearly dictates otherwise. As used inthis specification and the appended claims, the term “or” is generallyemployed in its sense including “and/or” unless the content clearlydictates otherwise.

“Include,” “including,” or like terms means encompassing but not limitedto, that is, including and not exclusive. It should be noted that “top”and “bottom” (or other terms like “upper” and “lower”) are utilizedstrictly for relative descriptions and do not imply any overallorientation of the article in which the described element is located.

Disclosed herein are apparatuses and devices, for example write heads.Generally, write heads may be utilized to write data, or bits (or bytes)to magnetic recording media. Write heads can also be part of a largerdevice that can include other components, for example a reader forreading the magnetic recording media. In embodiments, the larger devicecan be referred to as a slider. Write heads according to embodimentsinclude modified side shields.

Herein the term “antiferromagnetic-coupling layer” or“antiferromagnetic-coupling layers” refers to a material or combinationof materials that causes adjacent magnetic films to align theirmagnetizations antiparallel to each other. A nonexhaustive list ofmaterials that can form an antiferromagnetic-coupling layer orantiferromagnetic coupling layers is: Ru, Cu, Pd, Cr, Au, Ag, and Mo.

FIG. 1A schematically depicts a write head 100. The write head 100 isshown from the air bearing surface (ABS). This view can also bedescribed as the view as seen from the magnetic recording media. A writehead 100 may include a magnetic write pole 110. The write pole 110,along with other components (such as a write coil and a return polewhich are not shown herein) may function to induce a magnetic field fromthe write pole that passes through at least a portion of a magneticrecording medium and back to the return pole. Although not required, thewrite pole 110 may have a trapezoidal shape as depicted in FIG. 1A.

The write pole 110 has four sides. The four sides (or edges) or surfacesof the write pole 110 can generally be identified based on the directionwhich the magnetic recording media moves past the write pole when inuse. The usual direction of movement of the magnetic recording mediawith respect to the write head is shown by the arrow in FIG. 1A. Basedon this direction of movement, the write pole has a leading surface 104,which is the first to reach the magnetic recording media and a trailingsurface 102, which is directly opposed to the leading surface 104. Thewrite pole 110 also has a first surface 106 and a second surface 108which are generally the third and fourth surfaces of the write pole 110.

Proximate (or adjacent or directly adjacent) to the write pole 110 onthe trailing surface 102 is a trailing gap 120 c. The trailing gap 120 ccan be made of non-magnetic materials. Proximate (or adjacent ordirectly adjacent) to the trailing gap 120 c is a trailing shield 140.The trailing shield 140 may be made of magnetic materials. Inembodiments, the trailing shield 140 may be made of soft ferromagneticmaterials including, for example, alloys of NiFe, CoFe, and NiFeCo.

Proximate (or adjacent or directly adjacent) to the write pole 110 onthe first and second surfaces 106 and 108 are first and second side gaps120 a and 120 b. The first and second side gaps 120 a and 120 b can bemade of non-magnetic material. Proximate (or adjacent or directlyadjacent) to the first and second side gaps 120 a and 120 b are firstand second side shields 130 a and 130 b (which can also be referred tocollectively as “the side shields”). The first and second side shields130 a and 130 b may be made of magnetic materials. In embodiments, thefirst and second side shields 130 a and 130 b may be made of softferromagnetic materials including, for example, alloys of NiFe, CoFe,and NiFeCo. The first and second side shields 130 a and 130 b havetrailing shield surfaces 131 a and 131 b. The trailing shield surfaces131 a and 131 b are the surfaces of the first and second side shields130 a and 130 b that are most proximate to or closest to the trailingshield 140.

Write head 100 also includes first and second antiferromagnetic-couplinglayers 135 a and 135 b. It should be noted that first and secondantiferromagnetic-coupling layers 135 a and 135 b can also be considereda single layer of material in that the write pole 110 and the gapssimply interrupt this single layer. The first and secondantiferromagnetic-coupling layers 135 a and 135 b (which can also bereferred to collectively as “the antiferromagnetic-coupling layers” or“antiferromagnetic coupling layer”) are positioned between the trailingshield 140 and the trailing shield surfaces 131 a and 131 b of the sideshields 130 a and 103 b. In embodiments, the position of theantiferromagnetic-coupling layers can be more specifically identified.As seen in FIG. 1A, the first and second antiferromagnetic-couplinglayers 135 a and 135 b can be described as having bottom surfaces 134 aand 134 b. In embodiments, the bottom surfaces 134 a and 134 b of theantiferromagnetic-coupling layers 135 a and 135 b can be insubstantially the same plane (as used herein, “substantially the sameplane” can mean that the two surfaces are within ±5 nm of each other) asthe trailing surface 102 of the magnetic write pole 110. In embodiments,the bottom surfaces 134 a and 134 b of the antiferromagnetic-couplinglayers 135 a and 135 b can be in the same plane as the trailing surface102 of the magnetic write pole 110. Embodiments where the bottomsurfaces of the antiferromagnetic-coupling layers are at leastsubstantially in the same plane as the trailing surface of the writepole can provide advantageous levels of erasure fields and fielduniformity.

The number of individual layers that can make up anantiferromagnetic-coupling layer can depend at least in part onpre-determined properties of the side shields. Overall, increasing thenumber of individual layers may decrease both the erasure and theshielding effect. The position of an antiferromagnetic-coupling layercan also be determined to provide various effects. The number ofindividual layers making up an antiferromagnetic-coupling layer, theposition of the antiferromagnetic-coupling layer and other similarperformance parameters can be determined based on a number of factors,including for example, pre-determined reductions in erasure fields andimprovements in cross-track gradients which can be antagonistic.

In embodiments, the trailing shield 140 can be adjacent to (or directlyadjacent to or in physical contact with) the first and secondantiferromagnetic-coupling layers 135 a and 135 b. In embodiments, thefirst and second antiferromagnetic-coupling layers 135 a and 135 b canbe adjacent to (or directly adjacent to or in physical contact with) thefirst and second side shields 130 a and 130 b. In embodiments, thetrailing shield 140 can be adjacent to (or directly adjacent to or inphysical contact with) the first and second antiferromagnetic-couplinglayers 135 a and 135 b; and the first and secondantiferromagnetic-coupling layers 135 a and 135 b can be adjacent to (ordirectly adjacent to or in physical contact with) the first and secondside shields 130 a and 130 b.

In such an embodiment, the trailing shield, theantiferromagnetic-coupling layers, and the side shields can constitute asingle body that is made up of different materials. The differentmaterials can be deposited in stepwise fashion or can be depositedseparately and put together after deposition, for example. The trailingshield 140, antiferromagnetic-coupling layers 135 a and 135 b, and firstand second side shields 130 a and 130 b may also include other layers.

The antiferromagnetic-coupling layers may be made of anyantiferromagnetic-coupling material or more than one type ofantiferromagnetic-coupling material. In embodiments, theantiferromagnetic-coupling material can have an exchange couplingconstant of at least about 0.1 erg/cm², for example.

In embodiments, the first antiferromagnetic-coupling layer can be madeof a different material than the second antiferromagnetic-couplinglayer. Types of materials that may be used can include, for example Ru,Cr, Pd, Cu, Au, Ag, and Mo. Specific types of materials that may be usedin the antiferromagnetic-coupling layers can include, for example, Ru orCr. In embodiments, the antiferromagnetic-coupling layers can includeRu.

Without utilizing write heads as disclosed herein, the steady statesituation of write poles may not be effectively addressed. Because thewrite pole and the shields are both magnetic, charges of oppositepolarity can be induced in the shields (both trailing shield and sideshields) by the write pole. This is schematically depicted in FIG. 2A.For example, the write pole 210 can be positively charged and theshields (trailing shield 240, first side shield 260 a and second sideshield 260 b) can be negatively charged. When both the trailing shieldand the side shields are negatively charged (or both positivelycharged), crosstrack and downtrack gradients can be enabled. Dynamicerasure fields that correspond to the generation of transient charges inthe side shields of the same polarity as the write pole, that can beinduced by such a situation can be seen in FIG. 2B.

In embodiments that include antiferromagnetic-coupling layers, theopposite charges, created by the leakage from the write pole and theundershoot, created by the flux path from the write pole into the softunderlayer and into the side shields, appear in close proximity to eachother, on the opposite sides of the antiferromagnetic-coupling layer(i.e., in first antiferromagnetic-coupling layer 235 a and secondantiferromagnetic-coupling layer 235 b). This may prevent or minimizethe same polarity (as the write pole) charges from spreading into thetrailing shield, as seen in FIG. 2C, which could significantly affectthe writer performance by reducing the downtrack gradient. This may alsoreduce (in some embodiments significantly) the erasure field generatedin the media plane. This reduction may take place even though thedensity of the same polarity charges remains significant, because theyare now in a close proximity to the charges of the opposite polarity, asseen in FIG. 2C.

Dynamic erasure fields that can be induced by such a situation can beseen in FIG. 2D. As seen in FIG. 2D, inclusion of a singleantiferromagnetic-coupling layer 235 can significantly reduce themaximum erasure fields (to 1000+Oe (FIG. 2D) from 3-4 KOe in FIG. 2B).

Write heads can also optionally include stacks. A write head 300 thatincludes optional first and second layered structures (the first andsecond layered structures can also be referred to herein as “the layeredstructures”) is depicted in FIG. 3. In embodiments that include optionallayered structures 305 a and 305 b, the first and secondantiferromagnetic-coupling layers 336 a and 336 b can be disposed withinthe first and second layered structures 305 a and 305 b respectively.The layered structures 305 a and 305 b may also include upper and lowermagnetic layers. In the embodiment depicted in FIG. 3, the first layeredstructure 305 a includes an upper magnetic layer 340 a and a lowermagnetic layer 342 a, which sandwich the firstantiferromagnetic-coupling layer 336 a. This can also be described asthe first antiferromagnetic-coupling layer 336 a being positionedbetween the upper magnetic layer 340 a and the lower magnetic layer 342a. The second layered structure 305 b may have a similar structure, withsimilarly positioned layers. The optional layered structures may bepositioned between the trailing surfaces of the first and second sideshields and the trailing shield.

The antiferromagnetic-coupling layers that are positioned in theoptional layered structures can be made of the same materials as theantiferromagnetic-coupling layers discussed above. The upper and lowermagnetic layers may be made of magnetic materials that are more magneticthan the materials of the side shields. In embodiments, the upper andlower magnetic layers may be made of the same or different materials. Inembodiments, the upper and lower magnetic layers may be made ofmaterials that have a magnetic flux density of from 0.5 Tesla (T) to 2.4T. In embodiments, the upper and lower magnetic layers may be made ofmaterials that have a magnetic flux density of about 2.4 T.

In embodiments that include layered structures such as those depicted inFIG. 3, the antiferromagnetic-coupling layer can be positioned in asimilar fashion to that of the antiferromagnetic-coupling layer in theembodiment depicted in FIG. 2D, or can be positioned differently. Inembodiments, an antiferromagnetic-coupling layer in a layered structurecan be positioned between the trailing shield 340 and the trailingshield surfaces of the side shields 330 a and 330 b. In embodiments, theposition of the antiferromagnetic-coupling layer in layered structurescan be more specifically identified. For example, the top surfaces (thesurfaces adjacent to the upper magnetic layers 340 a and 340 b) of thefirst and second antiferromagnetic-coupling layers 336 a and 336 b canbe in substantially the same plane as the trailing surface of themagnetic write pole 310. In embodiments, the top surfaces (the surfacesadjacent to the upper magnetic layers 340 a and 340 b) of the first andsecond antiferromagnetic-coupling layers 336 a and 336 b can be in thesame plane as the trailing surface of the magnetic write pole 310.

Embodiments that include optional layered structures can function tofurther improve the antiferromagnetic coupling of theantiferromagnetic-coupling layer to the side shields and trailingshield. An example of how that can take place can be seen in FIG. 3. Asseen in FIG. 3, the upper 340 a (and 340 b) and lower 342 a (and 342 b)magnetic layers function along with the antiferromagnetic-couplinglayers 336 a (and 336 b) to enforce the opposite polarity of the sideshield 330 a (and 330 b) and the trailing shield 340.

Another example of a write head includes the write head 400 depicted inFIG. 4A. The write head 400 has an air bearing surface (ABS) andincludes a magnetic write pole 410. The write pole 410 has a firstsurface 406 and an opposing second surface 408. Proximate (or adjacentor directly adjacent) to the write pole 410 on the first and secondsurfaces 406 and 408 are first and second side gaps 420 a and 420 b. Thefirst and second side gaps 420 a and 420 b can be made of non-magneticmaterial. Proximate (or adjacent or directly adjacent) to the first andsecond side gaps 420 a and 420 b are first and second side shields 430 aand 430 b (which can also be referred to collectively as “the sideshields”). The first and second side shields 430 a and 430 b may be madeof magnetic materials. In embodiments, the first and second side shields430 a and 430 b may be made of soft ferromagnetic materials including,for example alloys of NiFe, CoFe, and NiFeCo. The first and second sideshields 430 a and 430 b have lower surfaces 431 a and 431 b. The lowersurfaces 431 a and 431 b are the surfaces of the first and second sideshields 430 a and 430 b that are most proximate to or closest to theABS.

Although the lower surfaces 431 a and 431 b are the surfaces of the sideshields that are closest to the ABS, they are located above the ABS. Byabove, it is meant that the lower surfaces of the first and second sideshields 430 a and 430 b are not substantially planar with the ABS, butare instead located farther from the magnetic media (when the write head400 is located with respect to magnetic media for purposes of writing tothe media) than the ABS is located from the magnetic media. This canalso be stated as the lower surfaces of the first and second sideshields 430 a and 430 b being more recessed from the ABS than the writepole 410 is located.

In embodiments, the lower surfaces 431 a and 431 b can be located arecess distance, R above the ABS. The recess distance, R_(a), of thelower surface 431 a of the first side shield 430 a and the recessdistance, R_(b), of the lower surface 431 b of the second side shield430 b are both shown in FIG. 4A. In embodiments, the recess distances,R_(a) and R_(b), can be the same or different. In embodiments, therecess distances can be from 10 nm to 70 nm. In embodiments, the recessdistances can be from 20 nm to 60 nm. In embodiments, the recessdistances can be from 35 nm to 45 nm. In embodiments, the recessdistances can be 40 nm.

Erasure events may occur when the charges in the side shields areconcentrated in a small area, creating large flux densities in themedia. If the side shields are recessed, such as the embodimentsdescribed herein, the created flux density due to localized charges canbe decreased (in embodiments significantly decreased). If the fact thatlarge concentrations of charges of one polarity always results ingeneration of charges of the opposite polarity is also considered, thenat a distance, such charges of opposite polarities may effectivelyscreen each other. This can further reduce the field experienced by themedia when side shields are recessed as described herein.

Write heads having recessed side shields can function to reduce erasurebecause the magnetic field from the side shields decreases as thedistance away from the side shield increases. Therefore, if the sideshield is located farther away from the media, the field strength at thelevel of the medium caused by the side shields will not be high enoughto cause erasure.

Another example of a write head includes a write head 401 depicted inFIG. 4B. The write head 401 has an air bearing surface (ABS) andincludes a magnetic write pole 411. The write pole 411 has a firstsurface 407 and an opposing second surface 409. Proximate (or adjacentor directly adjacent) to the write pole 411 on the first and secondsurfaces 407 and 409 are first and second side gaps 421 a and 421 b. Thefirst and second side gaps 421 a and 421 b can be made of non-magneticmaterial. Proximate (or adjacent or directly adjacent) to the first andsecond side gaps 421 a and 421 b are first and second side shields 432 aand 432 b (which can also be referred to collectively as “the sideshields”).

The side shields can include at least a high magnetic material portionand a low magnetic material portion. This is illustrated for the firstside shield 432 a that includes a high magnetic material portion 425 aand a low magnetic material portion 427 a. The low magnetic materialportions 427 a and 427 b can be further described as having lowersurfaces 428 a and 428 b respectively. The low magnetic material potion427 a is proximate to (adjacent to or directly adjacent to) the ABS. Inembodiments, the lower surfaces 428 a and 428 b of the low magneticmaterial portion 427 a and 427 b can be substantially planar with theair bearing surface ABS (as used herein, “substantially planar” can meanthat the three surfaces are within ±5 nm of each other).

In embodiments, the high magnetic portions 425 a and 425 b can beseparated from the low magnetic portions 427 a and 427 b by gaps 426 aand 426 b. The gaps 426 a and 426 b can be made of non-magneticmaterial, for example. The gap can be made of non-magnetic materialsincluding, for example AlO, FeO, SiO, and AlN. The gaps can be describedby their heights. The height of the first gap, G_(a), and the height ofthe second gap, G_(b) are both shown in FIG. 4B. In embodiments, theheights of the gaps, G_(a) and G_(b), can be the same or different. Inembodiments, the heights of the gaps can be from 10 nm to 70 nm. Inembodiments, the heights of the gaps can be from 20 nm to 60 nm. Inembodiments, the heights of the gaps can be from 35 nm to 45 nm. Inembodiments, the heights of the gaps can be 40 nm.

Materials of the high magnetic portion are more strongly magnetic thanmaterials of the low magnetic portion. In embodiments, the low magneticportion may be made of materials that have a magnetic flux density from0.1 T to 0.9 T. In embodiments, the low magnetic portion may be made ofmaterials that have a magnetic flux density from 0.3 T to 0.7 T. Inembodiments, the low magnetic portion may be made of materials that havea magnetic flux density from 0.4 T to 0.6 T. In embodiments, the lowmagnetic portion may be made of materials that have a magnetic fluxdensity of 0.5 T. In embodiments, the high magnetic portion may be madeof materials that have a magnetic flux density from 1.1 T to 2.4 T. Inembodiments, the high magnetic portion may be made of materials thathave a magnetic flux density from 1.3 T to 1.7 T. In embodiments, thehigh magnetic portion may be made of materials that have a magnetic fluxdensity from 1.4 T to 1.6 T. In embodiments, the high magnetic portionmay be made of materials that have a magnetic flux density of 1.5 T.Specific materials for the low magnetic portion may include, for exampleFeCo, FeNiCo, Ni, NiCo, and NiFe. Specific materials for the highmagnetic portion may include, for example FeCo, FeNiCo, Ni, NiCo, andNiFe. Specific materials for the low magnetic portion may include, forexample NiFe, FeCo, and FeNiCo. Specific materials for the high magneticportion may include, for example FeNiCo.

The low magnetic portion and the high magnetic portion can have the sameor different thicknesses. In embodiments, the low magnetic portion andthe high magnetic portion can independently have thicknesses of from 60nm to 140 nm. In embodiments, the low magnetic portion and the highmagnetic portion can independently have thicknesses of from 80 nm to 120nm. In embodiments, the low magnetic portion and the high magneticportion can independently have thicknesses of from 90 nm to 110 nm. Inembodiments, the low magnetic portion and the high magnetic portion canindependently have thicknesses of about 100 nm.

While recessed side shields (exemplified in FIG. 4A) can have lowerasure fields, their effectiveness in establishing a flux closure fromthe write pole into the soft underlayer and into the side shields canoften be somewhat reduced. This disadvantage can be compensated for byintroducing a multi-layer structure (exemplified in FIG. 4B), whererecessing the shields from the ABS layer is accompanied by a layer witha much lower magnetic moment, located at the ABS.

Write heads having shields that include a low magnetic portion and ahigh magnetic portion can function to reduce erasure because themagnetic field from the low magnetic portion (while closer to themagnetic media), may not be strong enough to cause erasure, but strongenough to establish a strong undershoot, and therefore good crosstrackgradients. The upper magnetic layer may also effectively screen anddissipate magnetic leakage fields from the write pole.

FIG. 5 shows the results of modeling the modified peak field(normalized) as a function of cross-track coordinates for a write headwith a conventionally designed side shields (60 nm gap between sideshields and the write pole, 2 T side shield material), side shields thathave a recess distance of 20 and 60 nm (dotted and dashed line) and sideshields that have a 0.5 T 60 nm thick low magnetic portion and a 2 T 60nm thick high magnetic portion with a gap distance of 40 nm (dot-dashline).

Thus, embodiments of WRITE HEADS WITH MODIFIED SIDE SHIELDS aredisclosed. The implementations described above and other implementationsare within the scope of the following claims. One skilled in the artwill appreciate that the present disclosure can be practiced withembodiments other than those disclosed. The disclosed embodiments arepresented for purposes of illustration and not limitation.

What is claimed is:
 1. A write head, the write head having an airbearing surface, the write head comprising: a magnetic write pole,wherein at the air bearing surface, the write pole has a trailingsurface, a leading surface that is opposite the trailing surface, andfirst and second surfaces; a trailing shield proximate the trailingsurface of the magnetic write pole; first and second gaps proximate thefirst and second surfaces of the magnetic write pole; first and secondside shields proximate the first and second gaps, each of the first andsecond side shields having a trailing shield surface; and first andsecond antiferromagnetic-coupling layers positioned between the trailingshield surfaces of the first and second side shields and the trailingshield, wherein the antiferromagnetic-coupling layers comprise anantiferromagnetic-coupling material having an exchange coupling constantof at least about 0.1 erg/cm².
 2. The write head according to claim 1,wherein the antiferromagnetic-coupling layers comprise Ru, Cr, Pd, Cu,Au, Ag, or Mo.
 3. The write head according to claim 1, wherein theantiferromagnetic-coupling layers comprise Ru.
 4. The write headaccording to claim 1, wherein the bottom surface of theantiferromagnetic-coupling layers are in substantially the same plane asthe trailing surface of the magnetic write pole.
 5. The write headaccording to claim 1, wherein the bottom surface of theantiferromagnetic-coupling layers are in the same plane as the trailingsurface of the magnetic write pole.
 6. The write head according to claim1, wherein the trailing shield physically contacts the first and secondantiferromagnetic-coupling layers and the first and secondantiferromagnetic-coupling layers physically contact the first andsecond side shields respectively.
 7. The write head according to claim1, wherein each of the first and second antiferromagnetic-couplinglayers are disposed in first and second layered structures, wherein eachof the first and second layered structures further comprise upper andlower magnetic layers, and wherein the antiferromagnetic-coupling layeris positioned between the upper and lower magnetic layers.
 8. The writehead according to claim 7, wherein the first and second layeredstructures are positioned between the trailing surfaces of the first andsecond side shields and the trailing shield.
 9. The write head accordingto claim 7, wherein the upper and lower magnetic layers comprise amaterial having a magnetic field of from about 0.5 to 2.4 Tesla.
 10. Thewrite head according to claim 7, wherein the upper and lower magneticlayers comprise a material having a magnetic field of about 2.4 Tesla.11. The write head according to claim 1, wherein theantiferromagnetic-coupling layer comprises a material that has anexchange coupling constant of at least about 0.1erg/cm.